Biparting elevator door interlock



Sept- 4, 1 1 N. R. GUILBERT, JR

BIPARTING ELEVATOR DOOR INTERLOCK Filed May 7, 1949 inventor NICHOLAS R.GU/LBERT, JR.

(Ittorneg Patented Sept. 4, 1951 UNITED STATES PATENT OFFICE BIPARTINGELEVATOR DOOR INTERLOCK Nicholas R. Guilbert, J r., Chestnut Hill, Pa.

Application May 7, 1949, Serial No. 91,949

15 Claims; 1

This invention relates to door locks, particularly to a safety lock fora biparting freight elevator door or the like for preventing operationof the elevator when the door is open as well as for preventing theopening of the door except when the elevator is stopped at orsubstantially at the floor level.

There have been proposed many types of so called door interlocks adaptedfor use in connection with elevator doors of various kinds, and somehave been reasonably satisfactory under normal conditions. Whensubjected to tampering, however, they may permit the elevator to beoperated while the doors are open, or the doors to be unlocked andopened when the elevator is at some other floor, either of whichpossibilities may. result in personal injury or loss of life as well asdamage to property and equipment.

It is therefore a principal object of the invention to provide aninterlock for biparting elevator doors which conforms to or exceedsexisting safety standards and which affords maximum security of personand property, even against efforts to jeopardize this security bytampering with the equipment.

Another object is to provide elevator door interlocking mechanismwhichis effective to securely lock the door panels at a floor entrance to thehatchway, to prevent the elevator being moved from the floor leveluntilthe panels'have been so locked, and to. prevent the doors from beingopened except while the elevator is at the floor level with its drivingmotor 'deenergized.

Other objects, purposes and advantages of the invention will hereaftermore fully appear or will be understood from the following descriptionof a preferred. and a modified embodiment of it wherein reference willbe had to the accompanying drawing in which:

. Fig. 1 is a fragmentary view in elevation from within the elevatorhatchway of the elevator door interlocking merchanism in operativerelation with vertically slidable panels of .a biparting'elevator doorof which but fragmentary parts are shown in association with a guiderail of conventional form,

Fig. 2 is a side elevation of the mechanism shown in Fig. 1, with thedoor panels, as in Fig. 1, closed and locked and Fig. 3 is a viewsimilar to Fig. 2 but with the door panels open.

Referring nowmore particularly to the draw ing it will be understood thedoor panels P, P, guide shoes S, S respectivelyattached to them, and theguide, {rail IR, which by en agement with the shoes maintains the panelsin approximate alignment for parallel movement away from and toward eachother to open and close the hatchway entrance may be of any suitablekind or character and form no part of the invention, as the doorinterlock with which the latter is directly concerned may be readilyadapted for effective operation in association and combination withsubstantially any biparting doors or other oppositely reciprocalelements, or in some instances may be employed in connection with but asingle door panel or other element in which case one of the lockinmembers may be omitted. It will be further understood the interlock asspecifically illustrated is designed for employment in connection withan electrically controlled elevator provided with an element known inthe art as a retiring cam carried bythe elevator and adapted to beprojected outwardly therefrom toward the adjacent hatch wall upondeenergization of the elevator driving circuit to stop the elevator andto be retracted preparatory to moving the elevator to another floor,although in a modification hereafter to be described the interlock mayreadily be adapted for use in association with a stationary camon theelevator.

Thus in its preferred embodiment the interlock as shown in the. drawingis positioned ad jacent the guide rail R and includes elements adaptedrespectively to engage a wing arm W on lower door panel P and lockbracket'L on the upper panel P" to lock the panels place-when the doorsare closed. The first of these elements, thelower latch arm I, ispivoted in 'aninterlock housing 2 on a transverse pivot pin 3 foroscillatory movement into and out of the path of the wing arm W on panelP while an upper latch arm 4, pivoted for movement about the same axisis movable into and out of the path of lock bracket L on panel P;' ifdesired springs, not shown, may be provided for urging the latch arms Iand 4 toward their locking positions illustrated in Fig. 2 as iscustomary in many types of door locking devices.

The upper latch arm 4 is provided with an angularly projecting rollerarm 5 carrying a roller 6, the position of which is desirably adjustablethrough the medium of a bolt I and nut 8 to enable the roller to be setat the appropriate posi tion for proper engagement by the retiring orstationary cam carried by the elevator so that when the latter stops ata floor the roller and hence the upper latch arm is moved thereby aboutthe axis of pivot pin 3 from locked position (Fig. 2) to unlockedposition (Fig. 3).

The lower latch arm I is provided with a bevel face I!) adapted forengagement by a striker cam I I carried by the lower panel P andprovided with any suitable mechanical or manual operating means forswinging it into engagement with the latch to move the latter out of thepath of the wing arm W when the door is to be opened. Thus it isapparent that when the door panels are closed, and with the latch armsin the positions illustratedin Fig. 2 thefdoors canngt be opened unlessthe latch arms are first moved out of the paths respectively of the lockbracket L and wing arm W. Normally these latch arms are movedrespectively by the elevator cam (not shown) and striker cam I I, thepanels usually being counterbalanced and so interconnected that whenboth are free to move either will move, in response to movement of theother.

The lower latch arm I however cannot be swung on its pivot to unlock thelower panel, either by operation ofthe striker cam or otherwise, unlessthe upper latch arm '4 has first been retracted since arm 4 comprises anintegral projecting arm I2 within the housing 2 which pivotallysupportsa depending tumbler I3 having-'a'n'inclined locking face I4 adapted forengagement by the complementary face I5 of an integral dog- IE on thelower latch arm I thus inhibiting movement of the latter when the partsare in locked (Fig. 2) position. The tumbler I3 is provided with a slotI7 through which a pin It extends into a boss IS on the inner face ofthe housing 2 whereby the tumbler can move freely substantially parallelto the inner face of the housing but is prevented by the pin and bossfrom being swung about its pivot by the dog I 6 on the lower latch arm.

There is also provided an electrical circuit in terlock whereby the mainelevator-motor driving circuit is held open when the latch arms areretracted, this circuit including a contact unit 28 containing a switchofanysuitable type connected in the motor control circuit in the usualway and provided with an operating arm 2i adapted for actuation by aContact control fork 22 which, when the elevator is provided with a re.-tiring cam, is desirably integral with or. relatively immovable withrespect to. roller arm 5. for movement therewith to. open said circuitwhen the roller arm is actuated: bythe retiring. cam. When the elevatoris, provided witha stationary cam however, it may be. preferableto. formthe con-. tact cont o fork Hintegral with or tosecure it to the lowerlatch a m Ir and to rearrange th ct n of e witch. in' Contact wait.v 201sov th main circuit is, interrupted; by, opening of the switch whenlower lza igck arm v I, is actuated, instead of b n nte rup e u en auation f e ro e It sy ss s, beta matte o c o e depending on con ons,which of the said arms is instrumental in actuating the contact controlf p ed. he lett r b araneed for si i actuation by one of;t lr em andmoves. correspondingly therewith to, actuatethe switch arm -2I to openand close the contact unit switch, and it will therefore, be evident theinterlock may be used equally well in associationwith' anelevatorprovided with a 'ietiring' cam or with one having a correspondinglypositioned stationary cam.

,As an additional safety measuremy interlock includes further mechanicalmeans for preventing tampering with the contact unit control to permitoperation of the elevator. while the doors are open, saidmeans'beingfully effective to produce this result under. normalconditions but also proof against improper effortsto prevent their ownnor-. mal operation" For this purpose there is pivoted 4 in the housing2 on a pivot pin 25 a rocker 26 having one arm 21 disposed forengagement by the upper edge of wing arm W to swing the rocker clockwisein Fig. 2 as the door closes, a dog 28 carried by the arm and adapted toabut the inner wall of housing 2 limiting movement of the rocker in thisdirection, and a second arm 29 disposed for engagement by the lower edgeof wing arm W to swing the rocker in the opposite direct e t e ev r isein Q eneehe arm 29 contacts a pin 36 projecting 'from the lower latcharm I when moved in the latter direction, whereby the latch is heldretracted by the rocker after the doorhas been opened, and to preventreverse movement or the rocker while the door remains open'there ispivoted to the lower end of arm 29 o end Of: a holding bar 3| the otherend of which all) is pivotally supported on a link 32 pivoted on a boss33 secured to the adjacent guide rail whereby the bar is constrained topartake of a substantially parallel motion when actuated by the rocker.This bar extends from the rocker arm 29 to a point close to the lowerend of the path of travel of wing arm W at which the latter seats onthe. usual adjustable sill support X and as the bar lies between saidpath and the hatch way wall adjacent the door jamb, the wing arm when intransverse alignment. with any part of it prevents the bar from beingmanually raised to swing the rocker on its pivot and the latter isthereby effectively locked against retraction except when the door isclosed orv substantially so and the wing arm thus cleared fromtransverse alignment with the bar. The bar when the door is open thusmaintains the. rocker substantially in the position illustrated in Fig.3 and under these conditions, the rocker through. engagement with pin 30holds. the lower. latch arm I retracted and the latter projecting itsdog I6. into the path of the tumbler I 3 holds theuppen latch arm 4'retracted even ifthe; retiring or other cam normally so holding it betampered with, and. while these sev eral parts are thus lacked inposition the. switch in contact unit- 20;:also remainslocked to preventcompletion of a circuit through the main driving motor to move.- the.elevator.

Wh le the: Operation. of the. apparatus heretofore deseribed'mayperhapsbe understood with: out furtherexplanation it may:- be noted thatit requiresno special; attentionfrom the elevator operator to i ns l leproper performance ofitsfu nctions as will; be; erident from a briefreference to the various. conditions. which arise automati-w cally;during thecycle. comprising'arrival of the elevator at;therfiooreleizel, opening and closing of the, door panels and;departure; of: the. elevator from the. floor. Ijhus;v as, the elevatorapproaches the; floor level, the door panelsP; P." and themterlock partsare in the several positions illustrated in'Fig. Asipreviously mentionedtheele- Vator may beeqiui-ppedz with. a retiring cam ora stationaryone;-- and: substantiallyas it reaches floor level and isbrought to astop the cam, ii of the former type isaprojected and engages roller 6 toactuate roller arm 5' and" latch arm}; or if the latter type likewiseengages theroller and similarly actuates the roller and latch arms; Ineither case the tumbler I3 is simultaneously and automatically moved outof the'path of dog IE; on

latch arm I, and if the cam is a 'retir ing one the cam II which can,now swing the latch arm I out of the path of the wing arm W due to thetumbler having been cleared from the path of the latch 'dog I6, As thelatch arm I moves, if the interlock is arranged for use with astationary cam on the elevator the contact unit switch open at thispoint rather than earlier in the cycle as it does when a retiring cam isused, and in either case as the door panels are moved in oppositedirections, either mechanically or manually, the wing arm W moves therocker 26 on its pivot to the position shown in Fig. 3 and through itssubsement alignment with the bar 3| maintain the rocker in position tokeep the latch arm I retracted through engagement with the latch pin'30.

Thus the latch arm I cannot be moved manually towards the interior ofthe hatchway while the door remains open, and as the latch dog I6therefore lies in the path of the tumbler I3 the upper latch arm 4 andthe roller arm 5 are also held retracted, so the contact unit switch iskept open no matter which latch arm is rigid with the contact unitcontrol fork 22, this depending, as noted, on whether a retiring or astationary cam is used on the elevator to actuate the roller arm 5. Whenthe doors are thereafter closed, as the wing arm W rises along theholding bar 3| and past the now retracted lower latch arm I it engagesthe upper arm 21 of the rocker 26 which was moved into its path bydepression of the lower arm 29 when the door was opened, and as the wingarm clears the notch of the latch arm I the latter can swing to lockingposition beneath it.

If the elevator cam is a retiring one it is retracted in the normal wayon actuation of the elevator control switch and this allows the roller-arm 5 and latch 4 to move to locking position and thereby close thecontact unit switch before the main driving motor is energized, usuallyby automatic' mechanism with which the present invention is notconcerned. If, however, a stationary cam is used the contact unit switchis closed simultaneously with the locking of the doors thus allowing theelevatorrto be operated, and as the said cam moves away from the roller6 the upper latch arm 4 is restored to locking position tolo'ck theupperdoor panel by engagement with 'lock'bracket L. In either case the partsare thus "restored to the positions shown in Fig. 2 with both doorpanelslockedl' As the main driving motor circuit is interconnected viaarmored cable 0 through contact unit 20 the switch in which is openedwhenever the door is unlocked either "accidentally or by design itisimpossible for the elevator to be operated at any position in thehatchway except when all doors giving access thereto and provided withmy interlock are closed 'and locked.

of the panels, such cams or their equivalents however forming no part ofthe mechanism which actually locks the panels when closed.-

Moreover as the parts are designed to afford adequate rigidity andstrength with great durability the interlock, which may readily beincorporated in either old or new elevator installations, when onceinstalled becomes a substantially permanent fixture normally requiringno attention except perhaps an occasional application of lubricant toits bearings to insure continuous service in the performance of itsintended functions, while the safety it affords from the standpoint ofboth mechanical and electric controls meets the standards of theUnderwriters Laboratories, required in many jurisdictions to permiterection and operation of elevators.

It will thus be I apparent my interlock is adapted for use withbiparting elevator doors of various types and in association withelevator installations of various kinds, and is effective to preventabnor'maloperation of the elevator and access to the hatchway from afloor in the absence of the elevator'without the slightest impairment ofor interference with it normal operation. I

While I have herein shown and described with considerable particularitycertain embodiments of the invention and referred especially to theiruse in conjunction with vertically'slidable biparting elevator doorssuch as are extensively used for freight elevators and the like it willbe understood that the principles of the invent-ion are applicable aswell in other installations, particularly those in which positivecontrol of an electric circuit in accordance'with the positioning of areciprocal element is required; therefore I do not desire or intend tolimit or confine the use of the invention to biparting elevator doors,as other uses for mechanism conforming thereto, and changes andmodifications in the form, construction and relationship of the severalparts of that embodiment thereof herein disclosed will readily occur tothose skilled in the art and may be made if desired, without departingfrom the spirit or scope of the invention as defined in the appendedclaims.

As my interlock is substantially a self contained unit which in itselfembodies all the parts essential for securely locking the door panelswhen the latter are provided respectively with a locking bracket and awing arm, or comparable latch engaging devices, it may be readilyincorporated in existing elevator installations as well as in new onesduring the course of their erection, the latches being adaptedrespectively for actuation improper sequence by a retiring or stationaryscam such as those long heretofore in use for oper- Havin thus describedmy invention, I claim and desire to protect by Letters Patent of theUnited States:

1. An interlock for a pair of oppositely reciprocal sliding door panelscomprising pivoted latch arms each adapted when in one positon to lockone of the panels against movement in one direction, a tumbler actuatedby one of the arms operative when the arms are in said position toinhibit movement of the other arm therefrom, and means carried by saidother arm operative when the tumbler has been moved from its inhibitingposition and said other arm moved from looking position to engage thetumbler to prevent its return to inhibiting position.

2. An interlock for a pair of oppositely reciprocal sliding door panelscomprising pivoted latch arms each adapted when in one position to lockone of the panels against movement in one direction, interengageablemeans carried by the ar'mscooperative-when the arms are in said positionto inhibit movement of one of them therefrom in advance of the other andto restrain return of said other arm to locking position while the firstarm remains out of said position.

3. An interlock fora pair of oppositely reciprocal sliding door panelscomprising pivoted latch a ms-eac ad edrh s -e s P0 1 to k one of thepanels against movement in one direction and movable about a commonaxisbetween locking and non-locking positions and means actuated by one ofthe arms when moved from looking to non-locking position operative whenthe arm is in the former position to inhibit movement'of the other armto non-locking position and operative when both arms are in the latterposition to inhibit movement of the first arm'to locking position. r a.An interlock for apair of oppositely reciprocal-sliding doorpanelsoomprising pivoted latch arms each adapted when in one position tolock one of the panels-against movement in one direction and movableabout a common axis between locking and non-locking positions, meansactuatedby one of the arms when moved from looking to non-lockingposition-operative when the arm is in the former position to inhibitmovement of the other arm to non-lookin position and. operative whenboth arms are in-the latter position to inhibit movement of the-firstarm to .locking position, and :means actuated by one of of-the armsoperative to interrupt an electrical circuit when said arm is moved fromlocking to non-looking position.

5. An interlock for a pair of oppositely reciprocal sliding door panelsdescribed comprising pivoted latch arms each adapted when in oneposition to lock one of the panels against move-- ment in one directionandmovable-about a common axis between locking and non-lockingpositions, means actuated by one of the arms when moved from looking tonon-locking position operative when the arm is in the former position toinhibit movement of the other arm to non-locking position and operativewhen .both arms are in the latter position to inhibit movement of thefirst 7 arm to locking position, and means en,- gageable with one of thearms and with an element carried by thepanel locking by -saidarmcherative to hold the latter in non-locking position whenever saidpanel is in a position other than that in which it is disposed whenlocked by said arm.

6. In combination with an elevator, an actuating cam carried thereby, abiparting door comprising upper-and lower vertically movable panels atan entrance to the elevator hatchivay, a looking bracket projecting fromand movable with the upper panel and a wing, arm projecting from andmovable with the lower panel, interlocking means comprising upperandllower .latchxarms respectively adapted to be engaged Joy *thebracket and the wing arm when disposed in the paths thereof, a switchdisposed, adjacent the latch arms, means actuated by one- -.of, thelatch arms for successively opening. and zclosing. the switch, a rollerarmprojecting from .the upper latch arm adapted for engagement-Joythesac tuating cam to movesaidarmrout oflthe path-ref the bracket and atumbler depending. from the upper latch arm-effective whensaid-arm-isrin said last mentioned. .pathto .inhibitmovement of thelower latch armout of' the path of the wing arm and effective .when thelower. latch arm is out of the path otthewingarm to inhibitmovement ofthe upper latch -arm, into'the pathof the bracket.

'7. In combination with an -ele;vator, an actuating cam carriedthereby.-and a-bipartingidoor comprising upperand lower verticallymovable panels at an .entranceto the, elevator rhatohway \alockingbracket projecting irom and movable with the upper panel and a wing armprojecting from-and movable with the lower panel, interlockingmeanscomprising upper and lower latch arms respectively adapted tobeengagedbythe bracket and the wing arm when disposed in the pathsthereof, a roller arm projecting from the upper latch arm adapted forengagement by the actuating cam to move said arm out of the path of thebracket a tumbler depending from the upper latch arm effective when'saidarm is in said path to inhibit movement of the lower latch arm out ofthepath of the wing arm and effective whenthe lower latch arm isout ofsaid last mentioned path to in'hibit movement of the upper latch arminto the path of the bracket, and means interconnected with the lowerlatch arm operable when said arm is out of the path of the wing armand'th'e wing arm is out of'thepeth ofsaid latch arm to inhibit movementof the latter intothepath of the wing arm.

8. In combination with an elevator, at bipartlng door comprising upperand lower vertically movable door panels at an entrance to the elevatorhatchway, a locking bracket projecting from and movable with the upperpanel, and a wing arm projecting from and movable with the lower panel,interlocking means comprising upper'and lower latch arms respectivelyadapted to. be enstaged by the bracket and the wing arm when cl-ispcsedin the paths thereof, means interconmeeting the latch arms operative toinhibit movements otherwise than in accordance within. predeterminedcycle which, beginning with the latch arms disposed in positionsrespectively for engagement by said bracket and said wing arm includessuccessively movement of the upper latch arm out of thepath oi.thebracket, movement of the lower latch. arm out of the path 101' thewing arm, movement of the lower latch arm intotthe ,path of the Whig-armand movement of the upper latch arm intothe path of the bracket, andmeans for moving said latch armsseouen- ,tial-ly out of the paths of thebracket and Wing.

arm.

--9. .In combination with an elevator, .an actuating oam carried therebyand a :biparti'ng door comprising upper and lower vertically movabledoor panelsat an ent'rance. to the elevator h'atfdhway, a lockingbracket projecting .from ,andlmovable with :the upper panel, awingarmprojecting from and movable with. the lower panel, interlockingmeansscomprising upper and lower latch arms respectively adapted to .beengagedbyithe bracket andzthe wing arm whendisposedinuthe paths thereof,means interconnecting .the latch arms operative to inhibit theirmovements other wise: than in accordance with. a predetermined:eyclewhich, beginning with the latch arms-dis- ;posed :in positionsrespectively for engagement by said bracket and said wing arm,includes-successively movement vof the. upper latch arm {out or the:path; of the '-.bracket. :movement of. the lower latch arm out'of thepath of the wingrfarm, movement 'of theazlower latch arm into .the.pathofthervwing farm and movement of thenpper latch: arm :into the.path .of the bracket, {and means engageable with :the wing.armionrestreiim Iing movement of=the lower latch armaintoethe path :ofthe-wing armaafteritlhas been .moved 10-. :In'combination .withaslidableelevatorfioor panel and a-wingarmoarried thereby, la; pivotedlatcharm projectib'le into and out of the path of the wing arm when thepanel is in closed position, a movable bar extending parallel to saidpath, pivoted links supporting the bar operative to maintain it inparallelism with said path during movement transversely thereof, andmeans projecting from the latch arm engageable by one of said links tomaintain the latch arm retracted from the path of the wing arm when thebar has been moved in one direction transversely of said path, the wingarm when the panel is in open position lying adjacent said bar in aposition to obstruct its corresponding movement in the oppositedirection.

11. An elevator door interlock comprising movable latch armsrespectively adapted in one position to lock one of the panels of abiparting elevator door when closed, and means interconnecting the latcharms operative to hold one arm in said position when the other arm is inthe corresponding position and to hold said other arm in a differentposition when the first arm is in a correspondingly different position,said means comprising a latch dog movable with the first arm and atumbler engageable by the dog pivoted to and movable with the second armand disposed in the path of the dog when the arms are in said firstposition, said dog being disposed in the path of the tumbler when thearms are in the second position.

12. An elevator door interlock comprising movable latch armsrespectively adapted to lock one of the panels of a biparting elevatordoor-when closed, and means interconnecting the latch arms operative tohold one arm in looking position when the other arm is in thecorresponding position and to inhibit the return of said other arm tolocking position when said first arm is in non-locking position, saidmeans comprising a latch dog movable with the first arm and a tumblerengageable by the dog pivoted to and movable with the second arm anddisposed in the path of the dog when the arms are in said firstposition, said dog being disposed in the path of the tumbler when thearms are in the second position.

13. An elevator door interlock comprising mov-- able latch arms forreleasably holding closed the panels of a biparting elevator door, meansinterconnecting the latch arms operative to lock one arm in position toso hold one panel when the other arm is in holding position with respectto the other panel, means for successively moving said last mentionedarm and then said first arm to other positions to release the panelsand, means carried by said last mentioned arm for holding it in saidother position when the first arm is in its said other position.

14. An elevator door interlock comprising movable latch arms eachadapted to releasably hold closed one of the panels of a bipartingelevator door, means interconnecting the latch arms operative to lockone arm in holding position when the other arm is in correspondingposition, means operable successively to move said other arm and thensaid first arm to non-holding positions and means for maintaining thefirst arm in its non-holding position while the corresponding door panelis open comprising a detent projecting from the arm, a pivoted leverengageable with said detent and means for actuating said lever.

15. In a door interlock for biparting elevator doors comprising opposedpanels and means supported by each panel adapted to engage a latch,upper and lower latches respectively adapted for engagement by saidmeans to lock the panels and interlocking means imposing a predeterminedsequence of operations on the latches in the cycle of successivelyunlocking and relocking the panels, comprising a tumbler carried by oneof the latches, and a latch dog carried by and movable with the otherlatch engageable with the tumbler to inhibit movement of the latterlatch when the tumbler and latch dog respectively are in predeterminedpositions and to inhibit movement of the tumbler-carrying latch when.the tumbler and dog respectively are in other positions.

NICHOLAS R. GUILBERT, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 543,569 Clark July 30, 18951,381,262 Wexler June 14, 1921

